Fiber board and process of manufacturing the same



enemies Nov. 11, 1924.

UNITED STATES 1514555 PATENT oFFIcE.

ALBERT L. GLAIP, OF DANVERS, MASSACHUSETTS, ASSIGNOR TO BEGKWITE, MANU-rnc'runme comm, or nosron, MASSACHUSETTS,

A. CORPORATION OF MAINE.

FIBER BOARD AND PROCESS OF MANUFACTURING THE SAME.

Ho Drawing.

To all whom it may concern:

Be it known that I, ALBERT L. CLAPP, a citizen of the United States,residin at Danvers, in the county of Essex and tate of Massachusetts,have invented new and useful Improvements in Fiber Board and Processesof Manufacturing the Same, of which the following is a specification,

This invention has for its objectto rovide a new material which iscapable o being formed into a hard horny mass or into sheets of anydesired thickness, and a process of making the same. I

I have discovered that, if animal matter such, for example, as tannedleather, ground bone or dried fish scraps are digested under heat andpressure with a large proportion of caustic alkali in the presence ofcellulose fiber, a solution is formed which permeates the fibers, andwhich may be subsequently precipitated therein by the employment of aprecipitating agent such as a metal salt, and that this material may bemolded, 'or formed into a single web or a composite sheet, and that theproduct is strong and more or less water-repellent. Thus I may produce apaper of high tensile strength, or a hard inflexible board, by varyingthe proportions of the components and the process 0 manipulating thefibrous mass.

For forming a. material somewhat like fiber board or leather board, onemay proa rapidly than be ore.

ceed as follows :-Into a digester, which may be closed, are introduced,say, 1000 pounds of cotton fibers (e. g., linters or cotton waste), andabout 300-500 pounds of comminuted tanned leather (or ground bone, or

such .dried fish scraps as are ordinarily used for fertilizers), andabout 15 pounds of caustic soda and enough water to submerge theforegoing ingredients. -The digester is closed, steam is injected fromtime to time until a pressure of about pounds is reached, and thecooking is continued for about four hours more or less. The tannic acidin the leather is neutralized and; the leather breaks down intosolution, and the solution permeates or impregnates the cotton fibers.The fibers because of the cooking, are rendered ca able of hydratingmore The contents of the digester are now withdrawn, and are placed inabeating engine with added water to a beating operation for about fivehours.

oipitating agent,

Application filed June as, 1920. Serial no. 391,163

Then I add to and beat into the mass 9. pree. g., aluminum sulphate,lead acetate or other suitable metal salt. This product is nowintroduced into a wet cylinder paper machine, and the fibrous mass isformed thereon in superposed convolutions until an encircling compositesheet of the desirable caliper is obtained, whereupon the sheet is slit,flattened, dried, and, if desired, compressed under high pressure.Instead of being formed into a web, the water may be squeezed from themass, and the latter molded in suitable molds under pressure.

It is quite evident that, instead of using cotton fiber, terials, suchas mechanical wood pulp or chemical wood pulp, e. g. sulphite or sodapulp, or the screenings of such pulp. For

example, a very strong and tough wrapping with a metallic salt in abeating engine, sub-,

sequent to the beating of the pulpy mass,

f then forming a sheet therefrom by any suitable sheet-forming papermachine. A sheet I may use other cellu'losic maso formed possessesgreater strength than paper of the same cali r formed in the usualmanner from sul ate. pulp. For the sulphate pulp, referre to in thisexample, I may substitute rag fiber, or cotton linters or waste, orground wood or soda or sulphite pulp, or them equivalents.

The digestion of the tanned leather -('or its equivalent) under highpressure and temperature with a large proportion of caustic soda,results in. a solution, which, according to Grahams test, isnon-colloidal, and thus is capable ofpermeating individual fibers. Thean' lution, 1s precipitated into waternsoluble precipitate, ingelatinous form which dries into a hard colloidal mass.

What I claim is 1. A process which comprises digesting cellulosicmaterial, animal matter and a caustic alkali with heat and pressure, andthen precipitating the animal matter in solution. p

2. A process which comprises digesting cellulosic material, animalmatter and a then precipitating the tion with a metal salt.

emma caustic alkaliwith'heat and pressure, and

animal matter in solu- 3. A process which comprises digesting'cellulosic material, animal caustic alkali with he ing the digestedmass matter and a at and pressure, beatwith water, and thenprecipitating the animal matterin solution with a metal salt.

4. A process which comprises digesting cellulosic material, animalcaustic alkali with he ing the digested mass matter and a at andpressure, beatwith water, then precipitating the animal matter insolution with a metal salt, and finally forming the pulpy 15 mass into asheet of desired thickness.

5. A fibrous material, the fibers and interstices of which contain aninsoluble colloidal precipitate, precipitated by a metal salt from thatnoncolloidal matter derived from the digestion of leather or the likewith a caustic alkali. ,i

In testimony whereof I have aflixed my signature. i

ALBERT L. CLAPP.

